The dependence of the etch mechanism of lithographically seeded macropores in low-doped p-type silicon on water and hydrofluoric acid (HF) concentrations has been investigated. Using different HF concentrations (prepared from 48 and 73 wt.% HF) in organic electrolytes, the pore morphologies of etched samples have been related to in situ impedance spectra (IS) obtained by Fast Fourier Transform ...

bioaerosols are the most significant risk for exposed people leads to infectious diseases. this study was aimed at evaluation of physical and microscopic characteristics and submicron particulate filtration efficiency of surgical masks used in hospitals throughout iran. five types of domestic (zist filter, elhamteb and arman masks) and imported (blosom, face masks) surgical masks were tested se...

mixed clayey soils occur as mixtures of sand (or gravel) and clay in widely varying proportions. their engineering behavior has not been comprehensively studied yet. an experimental program, comprising monotonic, cyclic, and post-cyclic triaxial tests was undertaken on compacted clay-granular material mixtures, having different proportions of clay and sand or gravel. this paper presents the res...

approach of organic material anaerobic biodegradation and species of organic matter in sediment are discussed, and then a classifying method of the species is proposed on a new viewpoint. the pore water sediment oxygen demand (sod) numerical model in bottom sediment system is proposed originally, which differs from other advection-dispersion-sorption (ads) model in adding a sod-creating term. t...

the parameters used to determine the trophic state of a water body are: total phosphorus (tp),transparency (secchi disk depth) and chlorophyll a. however, these parameters show strong seasonalfluctuations which may hinder the estimation of trophic state. some authors have proposed that sediments be used as an additional tool to evaluate the trophic state of a water body. the aim of this study w...

abstract at present study constant rate of strain (crs) consolidation under non-darcy condition was investigated. in this study a governing conditions of drainage pore water were investigated using proposed equation. the crs experiments under different rates of strain were conducted on different soil samples. results these experiments and there comparison with proposed equation showed that flow...

Expansive soils can be found in many parts of the world particularly in arid and semi-arid regions. These soilspose a significant hazard to civil engineering structures due to its high swelling and shrinkage potential. This paperpresents the results of an experimental program developed to investigate the effect of cyclic drying and wetting on theswelling potential of expansive soils with variou...

although some 3d slope stability algorithms have been proposed in recent three decades, still role of pore pressures in three dimensional slope stability analyses and considering the effects of pore water pressure in 3d slope stability studies needs to be investigated. in this paper, a limit analysis formulation for investigation of role of the pore water pressure in three dimensional slope sta...

Gelatin is considered as a partially degraded product of collagen and it is a biodegradable polymer which can be used to produce scaffolds for tissue engineering. Three-dimensional, porous gelatin scaffolds were fabricated by thermally induced phase separation and freeze-drying method. Their porous structure and pore size were characterized by scanning electron microscopy. Scaffolds with differ...